package pack0707;

import java.util.HashMap;
import java.util.Map;

//演示Map的常用方法
public class MapDemoB {

    public static void main(String[] args) {
        Map<String,String> map=new HashMap<>();

        map.put("a","aaaaaaaaaa");
        map.put("b","bbbbbbbbbb");
        map.put("c","cccccccccc");
        map.put("d","dddddddddd");

        System.out.println(map.size());
        System.out.println(map.isEmpty());
        map.clear();
        System.out.println(map.size());
    }


}
